Fuel-pump for reversible internal-combustion engines.



. K. J. E. HESSELMAN. FUEL PUMP FOB REVERSIBLE INTERNAL COMBUSTION ENGINES.

APPLICATION I'ILEDIAY 18, 1908. 906,022. Patented Dec. 8, 190

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K. .T. E. HESSELMAN. FUEL PUMP FOR REVERSIBLE INTERNAL COMBUSTION ENGINES.

APPLIOATION FILED MAY 18, 1908.

906,022, I Patented Dec. 8, 1908.

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To all whom it may concern:

Be it known that I, KNUT JONAS ELIAS HESSELMAN, a citizen of the Kingdom of Sweden, residing at. Stockholm, Sweden, have invented new and useful Improvements in Fuel-Pumps for Reversible Internal-Oombustion Engmes, of which the following is a specification.

This inventionlrelates to improvements in fuel-pumps for reversible internal combus- In reversible internal combustion engines it is generally necessary to cut off the supply of fuel when'the engine is to be reversed.

This will easily be understood from the-follow- A rev er-sible explosive engine ing reasoning.

When astern is ordered,

runs ahead.

, the machinist immediately adjusts the controlling means of the engine for the new direction of rotation, but on account of the inertia the engine will make some few revolutions ahead before he changesits direction of rotation. If fuel be supplied to the engine during the. said revolutions several complications. can occur, the results of which depend on the construction of the engine.

For instance, it may happen that the products of combustion escape through the airinlet ports. 7 In some casesthe engine is actually working during the said revolutions, which obviously delays the maneuver. The greatest danger is, however, found in such engines where the. fuel is supplied: to the engine chiefly during the first part of a period of a cycle. If such an engine rotates in a direction opposite to that for which the conadjusted, the fuel will be supplied during thecompression stroke, whereb counter-explosions can effect pressures w 'ch are sufficient. to spoil the engine.

As a rule it is in the most cases not sufiicient to. disconnect the fuel-pump before the re-.

versal of the engine, but it is necessary to so construct the said pump that it will'automatioally cease to supply fuel to the engine when the controlling means are adjusted for a new direction of rotation.

The object of the present invention is to provide such an arrangement of theoi1- ump.

The invention consists, combinatlon with the fue -pump of means for keeping the suction valve (or valves-or a correspondm -open during e whole pressure stroke of the pump or the greater part. thereof when the Specification of. Letters Patent. Application and May 1a, 1908. Serial No. 433,496.

rincipally, in the valve or valves) of the pump.

Patented .Dec. 8, 1908.

engine runs in a directionopposite to that for which thecontrolling means of the engine are adjusted, all as will be more particularly explained herebelow and pointed out in the claims.

In the accompanying drawing I have shown two forms of my invention. Figures .1 and 2 show two sections of the oneform at right angles to each other. Fig. 3 1s a sectional view of the other form. Fig. 4 1s a section at right angle to the section in Fig. 3 of a part of the second construction form. Fig. 5 is a side-view of a hand-lever shown in Fig. 3. Figs. 6, 7, 8 and 9 show details.

Referring to Fig. 1, 1 indicates the pumpcasing, 2 the pump-plunger and 3 a shaft which drives the pump-plunger by means of an eccentric or the like. The shaft 3 may be the crank-shaft or any other shaft driven therefromby means of a suitable gearing so as to change its direction of rotation at the same time as the engine is reversed. q

4 indicates the pressure-valve of the o1lpum and 5 the suction-valve thereof.

6 IS the pressure-pipe of the pump and 7 the suctionpipe. 7 A spring 8 tends topress the suction-valve 5 against its seat. Qn the shaft 3 is provided a sleeve 9 which is slidable on the shaftbut not rotatable on the same and has on its. circumference two recesses 10 and 11, by means of which the suction valve obtains the desired movement,

this movement being transmitted to the valve by means of a roller 12 j ournaled on a ivoted arm 13, a wedge 14 and a pm 15. he one recess is active in the one direction of rotation and the other in the opposite direction, and both recesses have such shape that the path of the roller 12 declines slowly counted in the ordinary direction of rotation for each cam to the lowest point 15 from which the path rises rapidly to the circumference of the sleeve The device described above works in the following manner. When the plunger 2 rises from its lowermost position sucks fuel through the suction va ve 5 which s ke t open by the pin 15, the roller 12 engag ng t s cylindrical :part of the sleeve 9. During the downward stroke the plunger 2 presses the fuel back through the suction va ve 5, until the roller 12 engaging the recess 1( (or 11) ermits the spring 8 .to close the said valve. en this is done the remaimng fuel is forced out through the pressure valve 4. The suction valve 5 is closed earher or later I according to the position of the wedge 1.4 and a j the shaft 3 rotates in the opposite direction and the recess 11 is placed opposite the roller 12. If, however, the shaft 3 rotates in the last mentioned direction and the recess 10 is opposite the roller 12, the pump will not deliver any fuel or it will deliver only a very small quantity thereof to the engine,

this depending thereon that the suction valve 5 is kept open during the whole pressure stroke of the plunger .or during the greater part thereof and t opportunity to close the suction valve immediately before, at or after the end of the pressure stroke according to the shape of the recess and the position of the wedge. The lat ter may be adjusted manually or by a governor or both.

The form shown in Figs. 3-, 4 and 5 differs from that described above in that the sleeve 9 is provided with cams 10 and 11 and that the spring 8 actuating thesuction valve 5 tends to keep the latter open, the cams being ada ted to close the said valve at the de- 'sire moments, and furtherin that the control of quantity of fuel supplied to the engine is accomplished by means of an eccentrically located pin 16 forming the pivot of a lever 17 which is pivotally connected to a longitudinally movable rod 18, supporting at its upper end a roller 12 actuated by the sleeve 9 and the cams 10 and 11 thereon. To the said lever 17 is connected a pin 19, or the like, the upper end of which actuates the suction valve 5 under the action of the spring 8. When the rod 18 is pressed down by one of the earns 10, 11, also the pin 19 moves .downwards and compresses the spring 8 thus ermitting the suction'valve to reach its seat.

The eccentrically located pin 16 may be adjusted by means of a hand-lever 20 on the pivot of which the said pin 16 is provided, or such adjustment may be accomplished automatically by a governor or both manually and automatically.

The most important practical difference between the form shown in Figs. 1 and 2 and that shown in Fi s. 3-5 consists, however, in that, when in t e former the sleeve 9 is adjusted from the one-position to the'other, the suction valve 5 is opened (if the adjustment takes place during a pressure-stroke of the pump) when the roller 12 engages the cylindrical part of the sleeve, the pump thus immediately ceasing to deliver fuel, which is not the case in the latter form unless the spring 8 is strong enough to overcome the pressure in the pump-casing.

In the form shown in Figs. 3-5 the action to act directly upon the lever 1 In cases where great pressures are effected e spring 8 is given edaoaa means of a wedge between the rod 18 and -the sleeve 9 instead of by the pin 16. The

spring 8 in Fig. 3 may, if desired, be. arranged in the pump it may be necessary to provide a relief valve for the suction valve of the pump. Such a device is shown in Fig. 6. A relief valve 21 is here provided in the suction valve 5, and both are actuated by the in or rod 1 5 in such a manner that the unloa ing-valve 21 is kept open somewhat longer than the suction-valve 5 and is opened somewhat earlier than the latter, so that the suction valve thus will be unloaded. A. corresponding'device ma be used in the form shown in Figs. 3-5.

Iilstead of having the excess of fuel flow back through the suction valve, one may provide a separate channel through which the said excess flows back, as is illustrated in Fig. 7. A channel 22 is in communication with the pressure-chamber of the pump, while another channel 23 is. in connection with the suction chamber or any other cham ber for taking up the fuel flowing back. A port 23 a connects the two channels 22 and 23 with each other and can be closed by means ofa needle valve 24 or the like. A cam 25 or 25 acts upon a roller 26 which transmits the motion to a hollow sliding piece 27 by means of a lever 28 and a wedge 29. When the sliding piece 27 moves downwards under the action'of the cam 25 or 25* the valve 24 is first closed by means of a spring 30, wherethe latter has passed'the roller 26 a spring 31 raises the sliding piece 27 and thereby also the valve 24 so that the port 23 is opened. Also in this case any other controlling member maybe substituted for the wedge 29, and the latter may be adjusted manually or by means of a governor.

Finally it may be pointed out that the control of the uantity of fuel delivered by the pump may e accomplished by means of one or. two helical cams 32 provided on the shaft 9 as is illustrated in Figs. 8 and 9 (Fig.

9 being a section on line A B in Fig. 8).

Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. The combination with a fuel pump for reversible internal combustion engines, comprising a shaft, a suction valve, and a plunger, of means for keeping the suction valve open during the major portion of the pressure stroke of the plunger, when the engine runs in a direction opposite to that for' which the controlling, means are adjusted; the said, first-mentioned meanscomprising a sleeve mounted on the shaft and slidable but not rotatable in relation to said shaft and aoaoae provided with two devices, one for each direction of rotation of the engine, and connected with andadaptedto operate the suction valve of thefuel pump.

2. The combination with a fuel pump for v reversible internal combustion engines, comprising a shaft, a suction valve, a relief valve in said suction valve, Land a plunger, of means for keeping the suction valve open loduring the major portion of the pressure stroke of the plunger, when the engine runs in direction opposite to that for which the controlling means are adjusted; the said, first-mentioned means comprisin a sleeve mounted on the shaft and slidab e but not rotatable in relation to said shaft, and pro-' vided with two devices, one for each direction of rotation of the engine, and connected with and adapted to operate the suction valve of the fuel pump.

3. The combination with a fuel pump for reversible internal combustion engines, comprising a shaft, a suction valve, a plunger, a suction chamber, a pressure chamber, a

chamber 22 communicatin with the suction and pressure chambers, a c amber 23, a port connecting said chambers 22 and 23, a valve controlling said port, and means for operating said valve, ofmeans for keeping the suction valve open during the major portion of the pressure stroke of the'plunger, when the engine runs in a direction opposite to that for which he controlling means .are adjusted; the said, first-mentionedmeans com rising a sleeve mounted on the shaft and s idable but not rotatable in relation to said shaft and provided with two devices, one for each direction of rotation of the engine, and connected with and ada ted to operate the suc- 40 tion valve of the fuel pum 4. The combination Witli a fuel pump for reversible internal combustion engines, comprisin a shaft, a suction valve, and a plunger, of means for keeping the suction valve open during the major portion of the pressure stroke of the plunger, when the engine runs in a direction opposite the controlling means are adjusted; the'said, first-mentioned means comprising a sleeve mounted on the shaft and slidable but not rotatable in relation to said shaft and provided with two devices, one for each direction of rotation of the engine and connected with and adapted to operate the suction valve of the fuel pump throu h a connection including adjustable means or determining the time at which the suction valve is closed.

5. The combinationwith a fuel pump for reversible mternal combustion engines, comprising ashaft, a plunger, a suction valve,

to that for which and controlling by the shaft for keeping the suction valve open during the major portion of the stroke 0 the plunger, when theengine runs in a direction opposite to thatfor which the controllin lg means are adjusted.

6. he combination with a fuel pump for reversible internal combustion engines, comprising a shaft, a suction valve, and a plunger, 0 means forkeeping the suctlon valve open during thevmajor portion of the pressure stroke of the plunger, when the engine runs in a direction opposite to that for which the controlling means are adjusted; the said first mentioned means comprisin a sleeve mounted on the shaft and slidab e but not rotatable in relation to said shaft and provided with two cams displaced in relation to each other and connected with the suction valve through a lever and pin.

7. The combination with a fuel pump for reversible internal combustion engines, comprisin a shaft, a suction valve, and a plunger, 0 means for keeping the suction valve open during the major portion of the pressure stroke of the plunger, when the en ine runs in a direction opposite to that for w ich the controlling means are adjusted; the said first mentioned means comprisin a sleeve .mounted on the shaft and slidable but not rotatable in relation to said shaft and provided with two cams displaced in relation to each other and connected with. the suction valve through a lever and pin, the pivot of the lever being ad'ustable.

8. The com ination with a fuel pump for reversible internal'combustion engines, comprisin a shaft, a suction valve, anda plunger, 0 means for keepingvthe suction valve open during the major portion of the pres.- sure stroke of the plunger, when the engine runs in a direction opposite to that for which the controlling means are adjusted; the said first-mentioned means comprisin a sleeve mounted on the shaft and slidab e but not rotatable in relation to said shaft and protion of rotation of the engine, and connected with and adapted to operate the I suction valve of the fuel ump, the said connection intermediate the s eeve and the suction valve including an adjustable wedge, for the purpose set forth.

, In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

KNUT JONAS ELIAS HESSELMAN. Witnesses:

, ERNEST DELMAR,

JOHN DELMAR.

means, of means controlled Y vided with two devices, one for each direc- 

